Question

ro 1 supra ro 2 =21/7 ,masa 1/masa 2=15/3 se cere V1/V2?

Answer 1

[tex]\tt Se~da:\\ \\ \frac{\rho_{1}}{\rho_{2}}=\frac{21}{7}\\ \\ \frac{m_{1}}{m_{2}}=\frac{15}{3}\\ \\ \frac{V_{1}}{V_{2}}=?\\ \\ \\ Formule: \\ \\ V=\frac{m}{\rho}\\ \\ \\ \frac{V_{1}}{V_{2}}=\frac{\frac{m_{1}}{\rho_{1}}}{\frac{m_{2}}{\rho_{2}}}\\ \\ \\ \frac{V_{1}}{V_{2}}=\frac{m_{1} \times \rho_{2}}{m_{2} \times \rho _{1}}\\ \\ \\ \frac{V_{1}}{V_{2}}=\frac{m_{1}}{m_{2}} \times \frac{1}{\frac{\rho_{1}}{\rho_{2}}}\\ \\ \\ Calcule:\\ \\ \frac{V_{1}}{V_{2}}=\frac{15}{3} \times \frac{1}{\frac{21}{7}}=\frac{5}{3}[/tex]

Answer 2

p1/p2 = 21/7 = 3
p1 = 3*p2
m1/m2 = 15/3 = 5
m1 = 5*m2
V1 = m1/p1
V2 = m2/p2 = 5*m1/3*p1
V1/V2 = (m1/p1)/(5*m1/3*p1)
=m1 : p1 : 5*m1 * 3*p1 cand desfacem o paranteza de dupa o impartire, in care se afla o inmultire sau o impartire se inverseaza semnul
=m1 : 5*m1 : p1 * 3*p1
=(m1 : 5*m1):(p1 : 3*p1)
=(1/5):(1/3) simplificam prima impartire cu m1 si a doua cu p1
=1/5 * 3/1 asa se face la impartirea fractiilor
=3/5
V1/V2 = 3/5